Local transplantation of ex vivo expanded bone marrow-derived CD34-positive cells accelerates fracture healing

Cell Transplant. 2012;21(12):2689-709. doi: 10.3727/096368912X654920. Epub 2012 Aug 27.

Abstract

Transplantation of bone marrow (BM) CD34(+) cells, an endothelial/hematopoietic progenitor-enriched cell population, has shown therapeutic efficiency in the treatment of ischemic diseases enhancing neovascularization. However, the number of CD34(+) cells obtained from bone marrow is not sufficient for routine clinical application. To overcome this issue, we developed a more efficient and clinically applicable CD34(+) cell expansion method. Seven-day ex vivo expansion culture of BM CD34(+) cells with a cocktail of five growth factors containing VEGF, SCF, IL-6, Flt-3 ligand, and TPO resulted in reproducible more than 20-fold increase in cell number. The favorable effect of the local transplantation of culture expanded (cEx)-BM CD34(+) cells on rat unhealing fractures was equivalent or higher than that of nonexpanded (fresh) BM CD34(+) cells exhibiting sufficient therapeutic outcome with frequent vasculogenic/osteogenic differentiation of transplanted cEx-BM CD34(+) cells and fresh BM CD34(+) cells as well as intrinsic enhancement of angiogenesis/osteogenesis at the treated fracture sites. Specifically, cEx-BM CD34(+) cell treatment demonstrated the best blood flow recovery at fracture sites compared with the nonexpanded BM CD34(+) cells. In vitro, cEx-BM CD34(+) cells showed higher colony/tube-forming capacity than nonexpanded BM CD34(+) cells. Both cells demonstrated differentiation potential into osteoblasts. Since fresh BM CD34(+) cells can be easily collected from fracture sites at the time of primary operation and stored for future use, autologous cEx-BM CD34(+) cell transplantation would be not only a simple but also a promising therapeutic strategy for unhealing fractures in the field of orthopedic trauma surgery.

MeSH terms

  • Animals
  • Antigens, CD34 / metabolism*
  • Blood Flow Velocity
  • Bone Marrow Cells / cytology*
  • Bone and Bones / blood supply
  • Cell Differentiation
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Female
  • Femoral Fractures / diagnostic imaging
  • Femoral Fractures / pathology
  • Femoral Fractures / therapy*
  • Hematopoietic Stem Cell Transplantation*
  • Hematopoietic Stem Cells / cytology*
  • Hematopoietic Stem Cells / metabolism
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Intercellular Signaling Peptides and Proteins / pharmacology
  • Male
  • Neovascularization, Pathologic
  • Osteogenesis
  • Rats
  • Rats, Nude
  • Tomography, X-Ray Computed
  • Young Adult

Substances

  • Antigens, CD34
  • Intercellular Signaling Peptides and Proteins